Rotary electrical connections are important in tools where an electrode is rotated to perform work within a hole, tube or tube type of plug. The present invention is an improved rotary electrical connection for use in tools or machines of the type which may employ rotating electrodes to perform operations such as welding or tube plug shrinking according to the method of U.S. Pat. No. 3,986,245, assigned to the same assignee as the present application.
The purpose of the new rotary electrical connector is to conduct a sustained or intermittent current from a fixed power source to a rotating electrode to produce a high frequency arc while presenting very little frictional resistance to rotation and heat damage to the rotating connector parts. It is ideal for use in a tool of the type which is small enough to be used on a job site, as for instance, within a nuclear steam generator.
When the rotary connector is utilized in a mechanical tube plug shrinker or rotary welder, benefits of compactness of the device, immunity of arcing to undesired ground paths and inherent stability and precise arc placement are provided. Moreover, the component parts of the rotary connector are readily available from commercial sources with sizes chosen on the basis of power requirements.